Comment on What are the most mindblowing fact in mathematics?

mookulator@lemmy.world ⁨1⁩ ⁨year⁩ ago

• cll7793@lemmy.world ⁨1⁩ ⁨year⁩ ago

  Thanks for the comment! It is cool also pretty aesthetically pleasing!

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  • Reliant1087@lemmy.world ⁨1⁩ ⁨year⁩ ago

    Your map made me think how interesting US would be if there were 4 major political parties. Maybe no one will win the presidential election 🤔

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• Blyfh@lemmy.world ⁨1⁩ ⁨year⁩ ago

  What about a hypothetical country that is shaped like a donut, and the hole is filled with four small countries? One of the countries must have the color of one of its neighbors, no?

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  • Afrazzle@sh.itjust.works ⁨1⁩ ⁨year⁩ ago

    I think the four small countries inside would each only have 2 neighbours. So you could take 2 that are diagonal and make them the same colour.

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    • SgtAStrawberry@lemmy.world ⁨1⁩ ⁨year⁩ ago

      Looks to be that way one of the examples given on the wiki page. It is still however an interesting theory, if four countries touching at a corner, are the diagonal countries neighbouring each other or not. It honestly feels like a question that will start a war somewhere at sometime, probably already has.

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      • Vegasimov@reddthat.com ⁨1⁩ ⁨year⁩ ago

        In graph theory there are vertices and edges, two shapes are adjacent if and only if they share an edge, vertices are not relevant to adjacency. As long as all countries subscribe to graph theory we should be safe

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    • Blyfh@lemmy.world ⁨1⁩ ⁨year⁩ ago

      But each small country has three neighbors! Two small ones, and always the big donut country. I attached a picture to my previous comment to make it more clear.

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      • Pronell@lemmy.world ⁨1⁩ ⁨year⁩ ago

        In your example the blue country could be yellow and that leaves the other yellow to be blue. Now no identical colors touch.

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      • Afrazzle@sh.itjust.works ⁨1⁩ ⁨year⁩ ago

        Whoops I should’ve been clearer I meant two neighbours within the donut. So the inside ones could be 2 or 3 colours and then the donut is one of the other 2 or the 1 remaining colour.

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    • ikilledlaurapalmer@lemmy.world ⁨1⁩ ⁨year⁩ ago

      Image Ok now do this one. What color is the donut country?

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      • BewilderedBeast@mander.xyz ⁨1⁩ ⁨year⁩ ago

        Image

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      • Afrazzle@sh.itjust.works ⁨1⁩ ⁨year⁩ ago

        Someone beat me to it, so I thought I’d also include the adjacency graph for the countries, it can be easier to see the solution to colouring them. Image

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  • BitSound@lemmy.world ⁨1⁩ ⁨year⁩ ago

    In that image, you could color yellow into purple since it’s not touching purple. Then, you could color the red inner piece to yellow, and have no red in the inner pieces.

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• sanguinepar@lemmy.world ⁨1⁩ ⁨year⁩ ago

  I read an interesting book about that once, will need to see if I can find the name of it.

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  • L3s@lemmy.world [bot] ⁨1⁩ ⁨year⁩ ago

    Read the author as Robin Williams

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• Artisian@lemmy.world ⁨1⁩ ⁨year⁩ ago

  Note you’ll need the regions to be connected (or allow yourself to color things differently if they are the same ‘country’ but disconnected). I forget if this causes problems for any world map.

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  • rycee@lemmy.world ⁨1⁩ ⁨year⁩ ago

    I suspect that the Belgium-Netherlands border defies any mathematical description.

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• dandroid@dandroid.app ⁨1⁩ ⁨year⁩ ago

  If you had a 3 dimensional map, would you need more colors to achieve the same results?

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• eran_morad@lemmy.world ⁨1⁩ ⁨year⁩ ago

  this whole thread is the shit.

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• clumsyninza@lemmy.world ⁨1⁩ ⁨year⁩ ago

  Isn’t the proof of this theorem like millions of pages long or something (proof done by a computer ) ? I mean how can you even be sure that it is correct ? There might be some error somewhere.

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